In the cyanate ion, OCN-, carbon is the central atom.
(d) Which h...

Question

In the cyanate ion, OCN-, carbon is the central atom.
(d) Which hybrid orbitals are used by the C atom, and how 
many p bonds does the C atom form?

Accepted Answer

Hey everyone, we're told that nitrogen is a central atom in di nitrogen oxide. How many pi bonds does the nitrogen atom create? And what hybrid orbital's did it use first? Let's go ahead and draw out our lewis structure. We want to determine the total number of electrons will have in our structure. So starting off with nitrogen, we know that this is in our group five a. So this will give us five valence electrons. Since we have two of nitrogen, we're going to multiply this by two and get a total of 10. Next looking at our oxygen, we know that oxygen is in our group 68. Since we have only one, we're going to get a total of six electrons. Now adding these two values up, we need a total of 16 electrons in our Lewis structure. So first let's go ahead and draw out our structure since nitrogen is less electro negative than oxygen, this will be our central atom. And in order to complete our 16 electrons, we get the following structure when nitrogen having a minus one charge on our left and our central nitrogen having a plus one formal charge. But let's go ahead and check if we can do resonance. So we actually can. And we end up with the following structure with three lone pairs on our oxygen and oxygen will have a formal charge of minus one while our central atom nitrogen will have a formal charge of plus one. And if we check on the other side, we also have another resonance structure where we have our left nitrogen with two lone pairs single bonded to our central nitrogen and our central nitrogen being triple bonded to our oxygen and our oxygen will have a minus one charge while our central nitrogen will have a plus one charge. Since we have two groups around the central element for all residents structures, this means that we will need to orbital's to accommodate these two groups and that's going to be an S orbital and a P orbital, which gets us to an sp hybrid orbital. Now let's go ahead and look at the pi bonds of each central nitrogen. Looking at our first structure to the left, we can see that we have one triple bond And one single bond, which means that we have two pi bonds. Looking at our second structure, we can see that we have two double bonds, which tells us that we also have two pi bonds. And lastly looking at our last structure, we also have that one triple bond and one single bond, which means we have two pi bonds. So for all structures are central atom, nitrogen had two pi bonds. So our answer here is going to be the central nitrogen. Adam has two pi bonds and it uses the sp hybrid orbital. Now I hope that made sense. And let us know if you have any questions

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